FUNCTIONALLY SUBSTITUTED SCHIFF BASES
217
methyl}benzoate (X). Yield 90%, light-yellow crystals,
mp 81–82°С. IR spectrum (KBr), ν, cm–1: 3090, 3047,
2970, 1740 (С=О), 1630 (C=N), 1537, 1375 (NO2). 1Н
NMR spectrum (CDCl3), δ, ppm: 3.97 s (3Н, Mе), 6.77 d
(1Harom, J 9.0 Hz), 7.96 d (2Harom, J 8.3 Hz), 8.18 d.d
(1Harom, J 9.0, 2.4 Hz), 8.20 d (2Harom, J 8.3 Hz), 8.40 d
(1Harom, J 8.3 Hz), (7Нarom, 3J 7.9–8.3, 4J 2.4 Hz), 10.11 s
(1Н, НC=N). 13C NMR spectrum (CDCl3), δ, ppm: 52.82,
112.56, 112.81, 116.56, 122.77, 124.37, 124.94, 128.92,
129.76, 130.43, 135.34, 138.43, 139.39, 149.83, 166.31,
191.89. Mass spectrum, m/z (Irel, %): 352 (68) [M]+.
Found, %: N 7.78. C16H11F3N2O4. Calculated, %: N 7.95.
(for azomethine XV at 0–5°С) and was left overnight.
The reaction mixture was diluted with 40–50 ml of
20% aqueous NaOH, The organic layer was separated,
washed with water, and dried with MgSO4. The solvent
was evaporated, the solid residue was recrystallized from
ethanol (XVI–XX) or from a mixture benzene–ethanol,
1:1 (XXI, XXII).
Reductive alkylation of amines I–IV with
4-methoxycarbonylbenzaldehyde (VIII). b. Asolution
of equimolar quantities (10 mmol) of amine I–IV and
aldehyde VIII in 30 ml of benzene was heated at 60°С
for 1–1.5 h, then cooled to room temperature, and the
mixture was poured at stirring to a cooled (0°С) mixture
of 20 mmol of NaBH4, 10 ml of benzene, and 60 mmol of
acetic acid. The obtained mixture was stirred for 30 min
at room temperature, then 6 h at 50°С. Reaction products
XVI–XIX were isolated as described above.
Methyl 4-{[(2-methyl-4-nitrophenyl)imino]methyl}-
benzoate (XI). Yield 64%, mp 202–203°С. IR spectrum
(KBr), ν, cm–1: 3065, 3040, 2970, 2910, 1720 (С=О),
1
1630 (С=N), 1530, 1350 (NO2). Н NMR spectrum
(CDCl3), δ, ppm: 2.43 s (3Н, Mе), 3.98 s (3Н, ОMе),
7.30 d (1Нarom, J 8.1 Hz), 7.75 d (1Нarom, J 8.1 Hz),
8.04 d (1Нarom, J 8.1 Hz), 8.09 d (2Нarom, J 8.1 Hz),
8.22 d (2Нarom, J 8.1 Hz), 8.50 s (1Н, НС=N). 13C NMR
spectrum (CDCl3), δ, ppm: 18.23, 52.69, 118.05, 118.41,
122.98, 125.76, 129.24, 130.35, 133.37, 139.40, 145.77,
156.59, 160.68, 166.62. Mass spectrum, m/z (Irel, %):
298 (100) [M]+. Found, %: С 64.35; Н 4.59; N 9.29.
C16H14N2O4. Calculated, %: С 64.43; Н 4.70; N 9.40.
Methyl 4-[(4-methyl-3-nitrophenylamino)methyl]
benzoate (XVI). Yield 90% (а), 80% (b), yellow
crystals, mp 107–108°С. IR spectrum (KBr), ν, cm–1:
3440 (NH), 1740 (С=О), 1520, 1360 (NO2), 1300,
1
1120. Н NMR spectrum (CDCl3), δ, ppm: 2.44 s (3Н,
Mе), 3.91 s (3Н, ОMе), 4.36 br.s (1Н, NH), 4.42 с (2Н,
СН2), 6.70 d.d (1Harom, J 8.3, 2.5 Hz), 7.08 d (1Harom
J 7.4 Hz), 7.20 d (1Harom, J 2.5 Hz), 7.41 d (2Harom
,
,
J 7.3 Hz), 8.01 d (2Harom, J 7.3 Hz). 13C NMR spectrum
(CDCl3), δ, ppm: 19.69, 48.11, 52.33, 108.21, 118.04,
122.34, 127.36, 129.74, 130.35, 133.59, 143.92, 146.73,
150.03, 167.02. Mass spectrum, m/z (Irel, %): 300 (100)
[M]+. Found, %: С 63.89; Н 5.14; N 9.25. C16H16N2O4.
Calculated, %: С 64.00; Н 5.33; N 9.33.
Methyl 4-({2-methyl-5-[4-(pyridin-3-yl)pyrimidin-
2-ylamino]phenylimino}methyl)benzoate (XIII). Yield
80%, yellow crystals, mp 193–194°С. IR spectrum (KBr),
ν, cm–1: 3410 (NH), 3040, 2970, 2910, 1725 (С=О), 1632
(С=N). 1Н NMR spectrum (CDCl3), δ, ppm: 2.36 s (3Н,
Mе), 3.96 s (3Н, ОMе), 7.18 d (1Нarom, J 4.9 Hz), 7.23 d
(1Нarom, J 8.9 Hz), 7.35 с (1Нarom), 7.40 m (2Нarom),
Methyl 4-{[4-nitro-2-(trifluoromethyl)phenyl-
amino]methyl}benzoate (XVII). Yield 60% (а), 55% (б),
yellow oily fluid. IR spectrum (film), ν, cm–1: 3450 (NH),
7.52 s (1Нarom), 8.04 d (2Нarom, J 8.1 Hz), 8.15 d (2Нarom
,
J 8.1 Hz), 8.35 d (1Нarom, J 7.8 Hz), 8.51 s (1H, НC=N),
8.52 d (1Нarom, J 4.9 Hz), 8.73 d (1Нarom, J 4.5 Hz), 9.30 s
(1Н, NH). 13С NMR spectrum (CDCl3), δ, ppm: 17.00,
29.42, 52.07, 107.93, 108.73, 117.05, 123.33, 126.55,
128.40, 129.71, 130.39, 131.98, 132.50, 134.12, 137.70,
139.94, 148.33, 150.51, 151.28, 158.10, 158.81, 160.13,
162.25, 166.38. Mass spectrum, m/z (Irel, %): 423 (82)
[M]+. Found, %: С 70.83; Н 4.79; N 16.37. C25H21N5O2.
Calculated, %: С 70.92; Н 4.96; N 16.55.
1
1720 (C=O), 1620, 1520, 1350 (NO2), 1130. Н NMR
spectrum (CDCl3), δ, ppm: 3.90 s (3Н, ОMе), 4.77 s (2Н,
СН2), 4.90 br.s (1Н, NH), 6.76 d (1Harom, J 9.0 Hz), 7.43 d
(2Harom, J 8.2 Hz), 8.02 d (2Harom, J 8.2 Hz), 8.17 d.d
(1Harom, J 9.0, 2.3 Hz), 8.39 d (1Harom, J 2.3 Hz). 13С
(CDCl3), δ, ppm: 51.67, 64.23, 115.89, 122.10, 123.70,
123.74, 126.02, 128.23, 128.86, 129.39, 138.49, 145.57,
149.23, 166.56. Mass spectrum, m/z (Irel, %): 354 (88) [M]+.
Found, %: N 7.75. C16H13F3N2O4. Calculated, %: N 7.91.
Reduction of azomethines IX–XV with sodium
borohydride. а. A solution or a slurry of 10 mmol of
azomethine IX–XV in 30 ml of benzene was added at
stirring to a cooled to 0°С mixture of 20 mmol of NaBH4,
10 ml of benzene, and 60 mmol of glacial acetic acid. The
reaction mixture was stirred for 6 h at room temperature
Methyl 4-[(2-methyl-4-nitrophenylamino)methyl]
benzoate (XVIII). Yield 88% (а), 79% (b), mp 182–
183°С. IR spectrum (KBr), ν, cm–1: 3410 (NH), 1735
(С=О), 1525, 1355 (NO2), 1320, 1100. 1Н NMR spectrum
(CDCl3), δ, ppm: 2.25 s (3Н, Mе), 3.92 s (3Н, ОMе),
4.57 d (2Н, СН2, 3J 3.9 Hz), 4.72 br.s (1Н, NH), 6.47 d
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 49 No. 2 2013